Leaking Radiator **confusion is real**

Jaronbwall · 01-05-2023, 09:02 AM

Hello N54 community,
So my radiator vent hose cracked, leaked out the coolant, and left me stranded. THANK GOD it was literally in an Autozone parking lot

I was able to replace it and build my own line with METAL barbs and screw clamps.
Fast forward 2 weeks and now my radiator is steaming and/or drying off coolant. Steam is coming out of the kidney grills. I removed the fan, pressure tested the system to 21psi, and can't find coolant dripping anywhere. I already replaced a lot of coolant lines, water pump and t-stat 3 years ago, but now I'm considering a CSF radiator replacement. Those are not cheap. Has anyone experienced the radiator end tanks (plastic) leaking or releasing steam when it's hot? Maybe it's pinhole leaks?

feuer · 01-06-2023, 12:51 AM

Could be just coolant residue from the leak on the radiator fins. Rinse it nice with water.

335i54n · 01-06-2023, 08:34 AM

its a pinhole leak in the rad, i would also run a scan for any pump faults

Jaronbwall · 01-06-2023, 01:46 PM

Quote:

Originally Posted by feuer

Could be just coolant residue from the leak on the radiator fins. Rinse it nice with water.

I was originally thinking the same thing but I drove it like that for a week.

Jaronbwall · 01-06-2023, 01:48 PM

335i54n The water pump is fine. No CEL or anything after the initial cracked coolant line. The fan is out so it seems like a reason to upgrade plus I'm considering running a track day this summer. Overheating is a known issue with the N54. Everyone upgrades these parts. NCM has long straights and a hot second gear corner according to YouTube videos.

Serf27 · 01-08-2023, 02:01 AM

The end tanks on these radiators leak more than you’d think.
My n54 driver end tank has been leaking for a while now.
It’s not severe and causes no issues on any drive, but it does randomly leak.

Jaronbwall · 01-12-2023, 11:51 AM

Serf27 That's so annoying. I ordered the CSF radiator. Can't wait to install it this weekend. Good time to clean the front side of the motor. It's disgusting from a leaking OFH gasket I replaced.

whyzee125 · 01-19-2023, 11:28 PM

At least CSF is an upgrade and a maintenance item so money well spent. Coolant does take a LONG time to burn off in my experience so it could be residual but you're talking about 14 year old plastic. You made the right move IMO

Jaronbwall · 01-23-2023, 07:09 AM

whyzee125 So I got the CSF radiator (beautiful product) from FCP Euro but I can't get it to fit. I've moved everything out of the way expect the oil cooler lines. There's literally no space between the AC lines and radiator end tanks. YouTube videos are saying it's tough but fits. I'm thinking something is off. Those lines don't really move that far. Any experience with this?

whyzee125 · 01-23-2023, 10:10 AM

Quote:

Originally Posted by Jaronbwall

whyzee125 So I got the CSF radiator (beautiful product) from FCP Euro but I can't get it to fit. I've moved everything out of the way expect the oil cooler lines. There's literally no space between the AC lines and radiator end tanks. YouTube videos are saying it's tough but fits. I'm thinking something is off. Those lines don't really move that far. Any experience with this?

Dang sorry to hear that. While I've always wanted a CSF, i've unfortunately never installed one. There are a few people running it on here though including I think feuer and SeanS54. I'm sure they could shed some light on it but I'd agree, that doensn't sound right as I've only heard good things about the CSF.

Jaronbwall · 01-23-2023, 11:17 AM

feuer SeanS54 Any advice on installing the CSF radiator? Not sure if forcing it down is the move or adjusting AC lines out of the way is ideal. I don't see you could drop it in straight down. Taking everything apart went good.

Thanks

Jaronbwall · 01-31-2023, 07:34 AM

Update: For anyone reading this my stock radiator was damaged after a coolant line busted. It developed hair line cracks (somewhere) on the end tanks. The CSF radiator fits amazing. After removing the oil cooler lines and pushing the AC lines over it dropped right in. ZERO GAP on the sides but fits. The mounting screws lined up nicely. Fan shroud fits fine. Car runs great and I no longer have leaking coolant in the engine bay. Easy time to replace the micky mouse flange and coolant hoses if you're in there. I had already replace that stuff. Cheers.

01-05-2023, 09:02 AM	#1
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	Leaking Radiator confusion is real Hello N54 community, So my radiator vent hose cracked, leaked out the coolant, and left me stranded. THANK GOD it was literally in an Autozone parking lot I was able to replace it and build my own line with METAL barbs and screw clamps. Fast forward 2 weeks and now my radiator is steaming and/or drying off coolant. Steam is coming out of the kidney grills. I removed the fan, pressure tested the system to 21psi, and can't find coolant dripping anywhere. I already replaced a lot of coolant lines, water pump and t-stat 3 years ago, but now I'm considering a CSF radiator replacement. Those are not cheap. Has anyone experienced the radiator end tanks (plastic) leaking or releasing steam when it's hot? Maybe it's pinhole leaks? __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava Last edited by Jaronbwall; 01-05-2023 at 11:45 AM..
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01-06-2023, 12:51 AM	#2
feuer Major General 4276 Rep 9,206 Posts Drives: wife crazy! Join Date: Apr 2015 Location: Chicago, IL iTrader: (5)	Could be just coolant residue from the leak on the radiator fins. Rinse it nice with water.
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01-06-2023, 08:34 AM	#3
335i54n Lieutenant 294 Rep 521 Posts Drives: e90 335i, e39 m5 Join Date: Nov 2020 Location: socal iTrader: (0)	its a pinhole leak in the rad, i would also run a scan for any pump faults
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01-06-2023, 01:48 PM	#5
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	335i54n The water pump is fine. No CEL or anything after the initial cracked coolant line. The fan is out so it seems like a reason to upgrade plus I'm considering running a track day this summer. Overheating is a known issue with the N54. Everyone upgrades these parts. NCM has long straights and a hot second gear corner according to YouTube videos. __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava
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01-08-2023, 02:01 AM	#6
Serf27 Brigadier General 2851 Rep 4,322 Posts Drives: 335i Join Date: Apr 2018 Location: Sitting in a BMW. iTrader: (-1)	The end tanks on these radiators leak more than you’d think. My n54 driver end tank has been leaking for a while now. It’s not severe and causes no issues on any drive, but it does randomly leak.
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01-12-2023, 11:51 AM	#7
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	Serf27 That's so annoying. I ordered the CSF radiator. Can't wait to install it this weekend. Good time to clean the front side of the motor. It's disgusting from a leaking OFH gasket I replaced. __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava
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01-19-2023, 11:28 PM	#8
whyzee125 Brigadier General 1673 Rep 3,640 Posts Drives: Dinan stage 2 335i Join Date: Jul 2014 Location: Chattanooga Tn iTrader: (0)	At least CSF is an upgrade and a maintenance item so money well spent. Coolant does take a LONG time to burn off in my experience so it could be residual but you're talking about 14 year old plastic. You made the right move IMO
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01-23-2023, 07:09 AM	#9
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	whyzee125 So I got the CSF radiator (beautiful product) from FCP Euro but I can't get it to fit. I've moved everything out of the way expect the oil cooler lines. There's literally no space between the AC lines and radiator end tanks. YouTube videos are saying it's tough but fits. I'm thinking something is off. Those lines don't really move that far. Any experience with this? __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava
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01-23-2023, 11:17 AM	#11
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	feuer SeanS54 Any advice on installing the CSF radiator? Not sure if forcing it down is the move or adjusting AC lines out of the way is ideal. I don't see you could drop it in straight down. Taking everything apart went good. Thanks __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava Last edited by Jaronbwall; 01-23-2023 at 11:22 AM..
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01-31-2023, 07:34 AM	#12
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,001 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	Update: For anyone reading this my stock radiator was damaged after a coolant line busted. It developed hair line cracks (somewhere) on the end tanks. The CSF radiator fits amazing. After removing the oil cooler lines and pushing the AC lines over it dropped right in. ZERO GAP on the sides but fits. The mounting screws lined up nicely. Fan shroud fits fine. Car runs great and I no longer have leaking coolant in the engine bay. Easy time to replace the micky mouse flange and coolant hoses if you're in there. I had already replace that stuff. Cheers. __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava Last edited by Jaronbwall; 02-20-2023 at 01:08 PM..
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